In a small bowl, whisk together the nonfat Greek yogurt, lemon juice, Dijon mustard, turmeric, sea salt, and black pepper until completely smooth.
Place the sauce in a small saucepan over very low heat, stirring constantly just until warm to the touch; do not let it simmer or the yogurt will curdle.
Heat a non-stick skillet over medium-high heat and sear the lean ham for 2 minutes per side until the edges are crispy and golden.
Remove the ham from the skillet and add the fresh baby spinach to the same pan, sautéing for 1 minute until just wilted.
Bring a medium pot of water to a gentle simmer with the white vinegar, then carefully poach the eggs for 3 minutes until the whites are set but yolks remain runny.
Toast the English muffin halves until golden brown and place them on a serving plate.
Layer the sautéed spinach and crispy ham onto the toasted muffin halves, then top each with a poached egg.
Spoon the warm, velvety hollandaise sauce over the eggs and serve immediately.